It is known in the art relating to carrier material fasteners to provide snap fasteners having separate stud and socket assemblies attached to edges or other portions of a garment, sheet or other product to removably secure such portions together by "snapping" the stud assembly into the socket assembly. Various types of snap fasteners in use include a pronged type and a center post type as well as others. In general, the stud and socket assemblies of these snap fastener sets each include two parts: (1) a connecting member having connecting means, either a stud or socket and (2) a retaining member. The connecting and retaining members are secured on opposite sides of the carrier material by retaining means such as (a) prongs and a prong-receiving annular recess or (b) a post and a post-receiving recess or flange. The prongs or post extend through the carrier material into the recess or flange and are interlocked therewith by forcing the connecting and retaining members together against the carrier material, thus deforming the prongs or post into or against the receiving recess or flange and fixedly attaching the connecting (stud or socket) member to the desired portion of the carrier material.
Prior tools which have been used for attaching snap fasteners to garments and other materials have ranged from complicated machine setups to simple manual means, such as a wooden thread spool held against the connecting member and struck several times with a hammer while the retaining member is seated against a solid surface and the retaining means are engaged. Such manual means may involve difficulty in maintaining alignment of the assembly members while applying the hammer blows which force the members together.
A prior art tool 10 intended for attaching Gripper brand snap assemblies to an edge of a carrier fabric is shown in FIG. 1. The tool 10 includes a base 11 having upstanding sides 12 that pivotally support a stabilizer arm 14 and a punch arm 15. The sides are ribbed, apparently to aid gripping with fingers in use. Near the end opposite the pivot axis 16, the base 11 carries a pair of longitudinally spaced flat bottomed recesses 18, 19 adapted to receive the retaining members of two different sizes of fasteners. The arm 14 includes guide openings 20, 22, respectively, aligned with the recesses 18, 19. The openings 20, 22 apparently locate the connector members of the snap assemblies prior to assembly. The arm 15 carries a pair of downwardly protruding punches 23, 24 sized to enter the guide openings 20, 22 and engage a connector member therein. Assembly would then be completed, presumably by striking the upper side of the arm 15 with a hammer opposite the location of the member engaging die. Raised areas 26, 27 on the top of the arm 15 opposite the punches indicate the locations for striking with the hammer. Only one snap assembly would be attached at one time in the appropriate sized one of the associated punch, opening and recess locations.
The prior tool 10 is adapted for use only with flat ended retainer members, cannot be used to apply snap assemblies to locations other than near the edges of a carrier material and is limited by the pivoting arms to use with a small range of thickness variations of the carrier material to which the snap assemblies are to be attached. As shown in FIG. 1, attempted use of a thicker than intended material 28 could cause excessive canting of the arms 14, 15 and the punch 23 and prevent the punch from pushing the members of the snap assembly squarely together, resulting in an unsatisfactory assembly. Also the shape and small size of the apparatus 10 makes holding with the fingers somewhat difficult and allows the possibility of striking the hand or finger with the hammer.